//
// Created by victor on 2021/6/24.
//

#ifndef OPENGL_SHADER_H
#define OPENGL_SHADER_H

#include <glad/glad.h>
#include <fstream>
#include <sstream>
#include <iostream>

class Shader {
public:
    unsigned int ID;

    Shader(const char *vertexPath, const char *fragmentPath) {
        std::string vertexCode;
        std::string fragmentCode;
        std::ifstream vShaderFile;
        std::ifstream fShaderFile;

        vShaderFile.exceptions(std::ifstream::failbit | std::ifstream::badbit);
        fShaderFile.exceptions(std::ifstream::failbit | std::ifstream::badbit);
        try {
            vShaderFile.open(vertexPath);
            fShaderFile.open(fragmentPath);
            std::stringstream vShaderStream, fShaderStream;

            vShaderStream << vShaderFile.rdbuf();
            fShaderStream << fShaderFile.rdbuf();

            vShaderFile.close();
            fShaderFile.close();

            vertexCode = vShaderStream.str();
            fragmentCode = fShaderStream.str();
        } catch (std::ifstream::failure &failure) {
            std::cout << "Error::SHADER::FILE_NOT_SUCCESSFULY_READ" << std::endl;
        }
        const char *vShaderCode = vertexCode.c_str();
        const char *fShaderCOde = fragmentCode.c_str();

        unsigned int vertex, fragment;
        vertex = glCreateShader(GL_VERTEX_SHADER);
        glShaderSource(vertex, 1, &vShaderCode, NULL);
        glCompileShader(vertex);
        checkCompileErrors(vertex, "VERTEX");

        fragment = glCreateShader(GL_FRAGMENT_SHADER);
        glShaderSource(fragment, 1, &fShaderCOde, NULL);
        glCompileShader(fragment);
        checkCompileErrors(fragment, "FRAGMENT");

        ID = glCreateProgram();
        glAttachShader(ID, vertex);
        glAttachShader(ID, fragment);
        glLinkProgram(ID);
        checkCompileErrors(ID, "PROGRAM");

        glDeleteShader(vertex);
        glDeleteShader(fragment);

    }

    void use() {
        glUseProgram(ID);
    }

    void setBool(const std::string &name,bool value) const{
        glUniform1i(glGetUniformLocation(ID, name.c_str()), (int) value);
    }

    void setInt(const std::string&name,int value) const{
        glUniform1i(glGetUniformLocation(ID, name.c_str()), value);
    }
    void setFloat(const std::string &name,float value)const{
        glUniform1f(glGetUniformLocation(ID,name.c_str()),value);
    }

private:
    void checkCompileErrors(unsigned int shader, std::string type) {
        int success;
        char infoLog[1024];
        if (type != "PROGRAM") {
            glGetShaderiv(shader, GL_COMPILE_STATUS, &success);
            if (!success) {
                glGetShaderInfoLog(shader, 1024, NULL, infoLog);
            }
        } else {
            glGetProgramiv(shader, GL_LINK_STATUS, &success);
            if (!success) {
                glGetProgramInfoLog(shader, 1024, NULL, infoLog);
            }
        }
        if (!success) {
            std::cout << "ERROR::" << type << " " << infoLog << std::endl;
        }
    }
};

#endif //OPENGL_SHADER_H
